The 10-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the fifth level hydrologic subdivision of the United States. A hydrologic unit can accept surface water from upstream drainage areas and may define a drainage area with … Continued
The 12-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the sixth level hydrologic subdivision of the United States. A hydrologic unit can accept surface water from upstream drainage areas and may define a drainage area with … Continued
The 2-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the major water resource regions of the United States. A water resource region is the first level of classification used by the United States Geological Survey to … Continued
The 4-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the second level hydrologic subdivision of the United States. A 4-digit hydrologic unit includes the area drained by a river system, a reach of a river and … Continued
The 6-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the third level hydrologic subdivision of the United States. A 6-digit hydrologic unit may subdivide a 4-digit hydrologic unit or may be equivalent. There are 401 6-digit … Continued
The 8-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the fourth level hydrologic subdivision of the United States. A hydrologic unit can accept surface water from upstream drainage areas and may define a drainage area with … Continued
Surface Texture is based on the composition of sand, silt, and clay in the surface layer of soil based on the standard soil triangle definition.
Soil Taxonomy Order, which is the broadest classification of soil types, has been updated to the October 2019 NRCS SSURGO data release.
Land Capability Class, which shows the general suitability of soils for agricultural purposes, has been updated to the October 2019 NRCS SSURGO data release. Note there is a change to the legend used to depict the data in this update.
The National Commodity Crop Productivity Index, or NCCPI, a rating of the non-irrigated productivity of the soil, has been updated to the October 2019 NRCS SSURGO data release.